Hi. I'm Aliza, a BC patient and Medical Librarian. I answer questions - usually non medical ones (librarians tend to avoid medical questions, even if we know the answers as it's practicing medicine sans license and of course, illegal). I also offer referrals to doctors, hospitals, institutions, agencies, websites, books, media, etc. as well as research when required or requested.
I'm also permitted to speak fro my own experience as a Cancer patient as well as those of family and friends (we number too many).
My advice to your friend would be to have your friend check with her doctor or perhaps better yet a registered dietician. A dietician would be the best person for knowing the most nutritious higher caloric foods that will help your friend gain weight. Consuming empty calories isn't the solution here.
I wish your friend luck and she seems to have fund some in having a good friend who's so concerned about her well being.
I might also recommend that your friend speak to the folks at CancerCare if she hasn't already done so. Their Social Workers are skilled in dealing with the very specialized needs of Cancer patients and their caregivers.
If there's anything else I can help with, I'm happy to do so, please feel free to contact me ere or offsite via email.